ROME, April 29 (Reuters) - Italian journalist Domenico Quirico, a correspondent for Turin's la Stampa newspaper, has not been heard from for 20 days after entering Syria from Lebanon earlier this month, the daily's editor-in-chief Mario Calabresi said on Monday.

The 62-year-old Quirico, an experienced war reporter, entered Syria on April 6 to report on the country's civil war, and has not been in contact since April 9.

After six days of silence, la Stampa together with the journalist's family contacted the Italian Foreign Ministry crisis unit, Calabresi said in an article published on the newspaper's website.

After a fruitless search for the reporter, it was decided to publicise his disappearance in the hope that it turns up some leads, Calabresi said.

Quirico has reported on conflicts in Sudan, Uganda and Libya and on the Arab spring uprisings, Calabresi said, and it was not uncommon for him to disappear for several days at a time, though never as many as 20.

The last time Quirico was in Mali, he was not heard from for six days, Calabresi said.

Four Italian journalists were kidnapped in Syria earlier this month, and were released after a little more than a week in captivity. The civil war has made Syria one of the most dangerous countries in the world, including for reporters. (Reporting by Steve Scherer; editing by Mike Collett-White)

Filipino journalists and supporters light candles to be placed on top of mock coffins during a rally to denounce killings of journalists in suburban Manila, Philippines on Friday, Nov. 23, 2012. Relatives and supporters of 58 people, including 32 media workers, massacred in the Philippines in the country's worst election violence held protest marches Friday to mark the third anniversary of the carnage to demand a speedy trial for nearly 200 suspects and an end to political killings. (AP Photo/Aaron Favila)